We also use Cisco and were seeing this issue earlier. It appears to have been significantly decreased after I disabled the IPTheft exclusion policy in lieu of Apple's aforementioned DHCP adherence to RFC4436.
On Cisco controllers, the capability described below appears to be called 'Dynamic Tx Power Control DTPC' "When you enable Dynamic Transmit Power Control (DTPC), access points add channel and transmit power information to beacons. (On access points that run Cisco IOS software, this feature is called world mode.)" It is enabled by default (at least in 6.0.182). Given Jeff's message below I'm thinking of disabling it. Is there any further info on this Broadcom driver bug/status? -- > -----Original Message----- > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > [mailto:wireless-...@listserv.educause.edu] On Behalf Of Jeffrey > Sessler > Sent: Wednesday, October 14, 2009 4:00 PM > To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU > Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs > > Are the Macs in question associating at 802.11a/n (5GHz)? I've posted > before about a bug in the Mac Broadcom driver which will cause the > client to continuously adjust it's power and may result in an > association to the AP but random communication issues (like failure to > get an IP). Cisco added a command to disable the World Mode IE feature > in the beacons until Apple fixes the problem. > > config 802.11a(or 802.11b) world-mode disable > > I think the above is in 5.2.193 but I'm not sure if it made it into > 6.0. I believe however that there is an equivalent individual AP cli > command for it. > > Oh, and world mode IE is disabled by default on Cisco autonomous AP's, > thus you'll likely not encounter the issue with them. > > Jeff > > >>> Anthony Croome <a.cro...@qut.edu.au> 10/13/2009 9:30 PM >>> > Hi > > We are having this problem too. Is there any new information from > people? > > We currently run Cisco wireless and have upgraded some locations to the > new N standard. > > The problem "appears" to be isolated in the locations where we have > upgraded but we can't be 100% sure. > > It is only appearing on macs, and they claim it works in one place but > not another. All we can see is that it appears to be rejecting the > dhcpoffer from the dhcp server. > > We haven't tried disabling dhcp proxy as discussed earlier in this > thread, but others have said it didn't help. > > The latest temporary solution that has worked on two out of two macs is > > === > > All commands required at the command line: > > sudo ipconfig set en1 BOOTP (case sensitive and en1 is generally the > wireless adapter on macs but it could possibly be different?) > > wait 5 seconds and then enter: > > sudo ipconfig set en1 DHCP > > === > > > Anthony Croome > QUT > > > -----Original Message----- > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > [mailto:wireless-...@listserv.educause.edu] On Behalf Of Earl Barfield > Sent: Friday, 28 August 2009 11:39 PM > To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU > Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs > > > Date: Thu, 27 Aug 2009 15:58:39 -0500 > > From: Hector J Rios <hr...@lsu.edu> > > Subject: Self-assigned IP on Macs... > > > > Have you guys run into this issue? We run Cisco's lightweight APs on > > WiSMs running code 5.2.193. Mac will associate to our APs but just > won't > > obtain an IP address. In the end it assigns itself a self-assigned > IP. > > We are seeing this on a lot of new MacBooks and MacBookPros running > > 10.5.8. If we associate the computer to an autonomous AP it works > fine. > > If we boot it in safe mode it works fine too. Everything else it just > > fails. > > I had the same problem after ugrading from 4.2.<something> to > 5.2.193.0. > > Uncheck "Enable DHCP Proxy" under controller->advanced->DHCP and see if > that fixes it. It worked for me. > > > -- > Earl Barfield -- Academic & Research Tech / Information Technology > Georgia Institute of Technology, Atlanta Georgia, 30332 > Internet: earl.barfi...@oit.gatech.edu e...@gatech.edu > > ********** > Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/groups/. > > ********** > Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/groups/. > > ********** > Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
